thomson



*"T"? 5b in Q '5 R y H I S. G. THOMSON CONVERTIBLE WHEEL STRUCTURE May 1, 1928.

S SheetS-Sheet 2 Filed Feb. 2. 1926 May 1, 1928.

S. G. THOMSON CONVERTIBLE WHEEL STRUCTURE Filed Feb. 2, 1926 6 Sheets-Sheet 3 May 1, I928; 1,668,092

' S. G. THOMSON CONVERTIBLE WHEEL STRUCTURE Filed Feb. 2. 1926 6 Sheets-Sheet 5 Patented May l, 1928.

reaaaaz earner caries.

SAMUEL G. THOMSON, NEW YORK, N.

CONVERTIBLE W'I-IEEL STRUCTURE.

Application filed February 7 This invention relates to a wheel structure having interchangeable treads adapted to convert the wheelstructure for use on either railway tracks or on highways.

It is well recognized that a vehicle can be operated over a'steel track with much greater economy than over the best built and smoothest highway, and many trafiic routes existthroughout the country which could profitably include a railway track for a considerable portionthereof, provided a wheel structure be available which allords a speedy change from rail to highway service and vice-versa. In that connection, the invention has in view the construction of such a wheel, whereby a vehicle equipped therewith may carry its load undisturbed and interchangeably over'both railway tracks and hi hways, thus adapting the vehicle to be used as adelivery and pick-up service, as well as for the longer hauls over the railay Having in view such conversion of a wheel, one of the primary objects of the invention is to provide a novel manner of mounting removable and interchangeable tread members on a wheel center in connecti on with which they are adapted to be used, preferably through the medium of clamping members and auxiliary devices such as will hold the tread members tightly in their operating positions, and at the same time by a few turns and quick movements permit such tread members to be interchanged with great facility, whereby the service of the vehicle may be changed in a small fraction of the time that would be required to unload and reload. goods, oreven to handle a dcmountable body. In this connection, the invention recognizes the necessity of the parts being held against looseiiess and rattle and yet permit them to be quickly and easily releasable.

function or railway track service and highway service,. it is essential that a wide variety of designs and combinations of clamping members are required to meet the ditierent needs in connection with the dir- Also that, 1 w in the conversion of a wheel having this dual 2, 1926. Serial. No. 85,512.

tion susceptible of a wide range of modifications without departing from the spirit i119; one form of this invention with the highway tread member shown in full lines and the rim portion of the railway tread member shown in dotted lines, to indicate that one of these members is interchangeable with the other..

Fig. 1 is a view similar'to Fig. 1 showing the highway tread member replaced by substituting'thcrefor the railway tread member; and in the succeeding figures of the drawings, to avoid multiplying the views, the rim portion of the interchangeable railway tread member is indicated by dotted lines, while its web or clamping flange portion is coincident with the same portion of the highway tread member. r

Fig. 2 is a similar view showing aslightly different form of the invention which is also a simplification thereof.

Figs. 3 and 4 are similar views showing novel forms of latch connecting means for uniting the wheel center, its treads and the holding or clamping means therefor.

Fig. 5 is a sectional view of a portion of a wheel showing a modified form of tread and center connection, in which the webs of the wheel center and ot' the treads contact for their full length, and are suitably interruring the detachable wheel treads to the wheel center. I

Figs. 11 and 12 represent sectional half views of types of wheel centers having cy-,

ice

lindrical contact faces for the tread members, and a. clamping ring or nut of very large diameter.

v l igs. 13 and, Il-lrepresent sectional halt views ot the same l1 jpes as those illustrated in lligs. l1 and 12, except that the c; linurical contacting faces for the tread members are of relatively smaller diameter.

Fig. isa sectional halt view illustrats ing a design in which the wheel-center is mounted on the usual journal of a fixed axle, and has a wide rim stiitiened by ribs joining it to the wheel web and hub.

Fig. 15 a detail side elevi'ition ig. 16 is i. sii'nilar view showing a design l 1 web is made slantmg v j TW' !7 ons oi lne iorm shown in a igs. .lt .1 the pOSriilFril of the treads laterally. and 2- are sectional hall views i.l designs similar to the forms 'gs. 9 and 10 relative to the bear- 7 tread member of the wheel centers; but these forms diller in that the structures shown here comprise internally driven roller bearing hubs of usual automotive design.

Fig. if)" is a transverse section showing a modification of the form illustrated in .l ig.

' .d is simila to the arrangement shown wo treads are employed t ly to provide a gauge or track width of the highway tread which sul antiall greater than that out the width ot the railr i tread.

l ig. 520" is a eransverse detail section showing a modification ot the form illustrated in Fig. 20. In this design, the two treads are separated lateriitlly, and the diameters oil the two treads differ consider ably.

Figs. 2t and 22 also represent sectional halt views illustrating other designs of wheels such as are en'iployed in automotive construction. Double-throw clamping rings are slunvu tor etmnocting the tread i'ueml'ier with the wheel center.

l igs. E23 and, 124. are trz'uisversc sectional halt views of wheels similar to those shown in Figs. 13 and 14.. except that in these ligures the usual automotive construction is iii-- eluded. liig. 2? shows the tread. members as having reinforced S-shaped plate disks or webs.

Fig. 24 is a detail transverse sectional view illustrating a modification of the form shown in Fig. 241, in which the highway tread has the inside position relative to the in i .17. in that, L and separated la eral This effects a narrower railway tread.

for the former than for the Fig. 26" is a similar view shoving a modilica'tion ot the form shown in Fig. 26, in 4 which the tread members and clamping plat s or cones are made integral.

i f2? a detail sectional view and illustrates a wheel center having a flange standinp up around one edge of its rim to engage the inner edges of the tread i'i'iembers, which J'ilflillJiE'ES may have a cushion or resilient. portion interposed between them and the wheel rim. i I

is a transverse sectional View of a portion of a wheel and illustrates a ribbed cast wheel center of the usual type for heavy auto trucks adapted to carry two separate highway tread members, and an interchangeable railway tread member.

Like references designate corresponding parts throughout the several figures of the t rawmgs.

This invention contemplates in the conversion 01" such a wheel for use on highways and railway tracks respectively, the provision of a common wheel center and interchangeable tread members, one of which is adapted for railway service and the other for highways, these tread members to be similarly constructed and attached so that they may be interchanged with great facility, thereby rendering this quick change "feature into one of the regular service facilities of the vehicle equipped with the interchangeable wheel structure.

1n carrying this invention into ellect it is proposed to interchangeably apply to a common wheel center desi nated generally as (l, the tread members 11 and ll, cachet which includes a web or spoke portion \V and a tread portion T. Other members common to the various forms and having the same designation are: the revolving axle or drive shaft A. ".ced axle or wheel-pin l ball or roller ljieariug ll. journal or jouruah bearing J, and driving sprocket or rack D.

()ne oi the distinctive features 01! this invention resides in so mounting the interchangeable tread memberson the wheel center that they may be speedily applied and removed, and which when applied, are securely held and yet quickly and easily released. Thereliore, a feature. tundamental to all forms of the invention and shown in ly and reliably mounting the detachable nil 1,668,092 I r I and interchangeable tread membcrs on the wheel center, and securely holding the parts. against looseness and rattle, the holding means utilized being designed and arranged to effectively maintain that relation be tween the wheel center and its tread mem bers.

The various forms may be classified according to the nature of the contact of the tread members with the wheel center. In this respect, it will be noted that the vertical 'webs lVoi'. the interchangeable tread members contact with a vertical. face of the wheel center C in Figs. 1, 2, 6, 10, ll, and 28, while in Figs. 3, l, 17 and 1S webs W contact with aconcave conical face of the wheel center; in Figs. 5, T, 8, 9, 16, 19'and 21 webs \V contact with a covex conical face of the wheel center, and in Figs. 11, 12, 15,

25 and 26 such contact is made'with'an outer face of the rim portion of the wheel center, which face is either cylindrical or very slightly conical and not far short of the working tread diameter of the wheel, while they contact with 'a face having a much smallerdiameter and which is substantially that of the outer face of thewheel hub in Figs. 13, 1 1-, 23 and 24-. In Fig. 20 the wheel center provides bearing faces for the interchangeable treadmembers in the form of cylindrical. and. vertical faces of a stepcone.

In order to bring out certain structural differences, the forms shown in the various figures of the drawings may be separated into two general classes comprising railway and wagon practice illustrated in Figs. 1 to 16 inclusive, and automotive practice, Figs. 17 to 26 inclusive. In the first class, all figures except 5, 6,15, 16, show the wheel center clamped on or keyed to a revoking axle of the railway type, whileFigs. 5, (3,

15 and 16 show a fixed axle with a journal bearing of the kind usually applied .to heavy wagons or automobile trucks. .i igs. 1 to l and 7 to let show a journal bearing and box applied inside of the wheel to a revolving axle in accordance withthe usual practice for engine trucks, it being of course understood that roller or other typos of antifriction bearings may be substituted in, lliesearrangements to allow tlieaxle to turn with the wheel.

In 17 to 20 and 23 to 26 are illustrated designs in which the wheel centeris attached to a driving shaft or revolving axle, the bearing being, either enclosed vwithin the wheel :hub and carried by a driving shaft housing, or located at the edge of the whee. hub and carried directly by the revolving axle or shaft. p

in the form shown in Figs. 21 and 22-, the wheel center ismounted on a fixed or swinging wheel pin by the use of roller bearings-enclosed within the hub.

a rack D for a chain drive.

It is to be understood that any suitable driving means for these wheels maybe enrployed. A rack D for chain drive shown attached to the wheel center in some of the designs, while in other designs. a driving shaft or axle A is either keyed to the internal bore of the wheel center or is extended through the bore and attached to the outer edge of the wheel hub.

In the embodiment illustrated in Fig. 1, the wheel. center C has a vertical clamping flange or. web carrying one or more pins designed to interlock with corresponding 'holes 3 formed inthe webs VI of the tread members, which webs are here shown vertical and contacting with the outer face of the vertical clamping flange 1 of the wheel center. This interlocking arrangement prevents relative movement between the wheel center and the tread members. In this form of the invention, the outer face of the hub 4- of the wheel center threaded and engaged by an internally threaded clamping dish or plate 5 and also by a jam nut 6 which coacts with said plate in locking the parts against backing off and becoming loose. In Fig. 2, the wheel center C has a vertical web Y provided around its perimeter with an offset flange-like member 8 which matches similar offsets 9 in the webs ll of the tread-.members H and R. The

tread members .in' this form of the invention are shown as having short bolting flanges which are bolted to the offset flange member 8 of the wheel center.

Another arrangement for connecting the tread members H and R with the wheel center C is shown in Fig. 3, in the form of a concave conical outer face or web 11 car ried by the wheel hub12, which hub has :been 'externall Y threaded as shown at 123 to The wheel center C has brackets 19 which project inwardly at intervals and support 7 It will thus be seen that the driving action of the chain around rack D will act positively through .the' interlocked pins 16 in delivering the power tothe tread member, which member may be either in the form of a highway 4. 1 z T tread. snown in full lines at pl or a railway tread member shown in dotted lmesat- E.

The 'wheelcenter C is ktyed to the rerill loll

volving axle A and held by the usual re taining collar and jam nuts 21 which are threaded around a projecting portion 22 of the axle A.

In the adaptation of the invent-ion shown in Fig. I, the tread members H and B have short inwardly projecting webs IV positioned at an incline to contact with the under face of an inclined flanged rim 23 carried by the periphery of the wheel center C. A clamping disk Bet has an out-turnwl clamping flange 25 which engages the tread web IV and holds it tightly against the under face of the rim 23 ot the wheel center. This disc .24. has a hub 26 threaded around the hub 01. the wheel center, said disk carry ing spring fittCl'lQS 27 which operate parallel with the body portion oi. the disk on the inner t'ace thereof and are d igncd to engage apertures in the web and flange 23, which apertures register to receive these latches. These laches operate to prevent relative rotation between the disk, the wheel tread and the wheel center. The disk as shown is equipped with operating handles 28 to facilitate its application and removal. In Fig. '5 the wheel center C has its web I provided with a convex conical outer face and an offset portion 29 at its perin'ietcr which is designed to assist in supporting the tread members H and R. In this form of the invention, the webs IV of the tread members are arranged obliquely and contact with the full width of the conical face of the wheel-center, and interlock with one or more pins 30 which project from this center. A clamping cone 31 has threaded engagement at its hub 32 with a combined clamping-nut and hub-cap 33, and bears against the web W of the tread member, said cone having apertures for engagement with the pins 30 which project from the tread member and which prevent relative rotation of these parts.

The clamping nut 33 has left-hand threaded engagement with the internally threaded hub of the clamping cone and right-hand threaded engagement with the wheel hub. This provides a double throw for the clamping parts as they are rotated by a wrench applied to the clamping nut, in the operation of applying and ren'ioving the tread members.

The clamping nut 33 has threaded engagement with the hub of the wheel center C, and is held against ri'itatiou by a key lit which. passes through the outer face of the cap and engages slots arranged around the enlarged end-bore ot the wheel hub. This key is inserted after the clamping members are drawn tight, and is held in place by a cotter pin 35 passing through the squared portion of the cap. In the form shown, the hub. of the wheel center C is internally bored to a bush-lining, which in turn contacts with the journal 01': a fixed axle F. The wheel is held to its position by the usual retaining collar 0 and jam nuts n.

The embodiment illustrated in Fig. 6 is similar to that shown in Fig. 5 as regards the journal bearing and double throw clamping members; but in this form, the web l of the wheel center C is vertical, and has large openings 36 spaced around the wheel, which openings are designed. to receive bearing projections 37 stamped out of the webs IV of the tread members II and R. A clan'iping cone 38 is threaded around the hub cap 33, and has projections 39 to extend inside the hollow projections 37 of the web IV and which operates to lock the parts against relative rotation. stood that the apertures 36 in. the wheel center and. the corresponding bearing projections 37 in the tread webs may be of any desired shape to afford good cooperating bearings and also used as means for lightening these members.

Other variations of the invention are shown in Figs. 7 and 8, wherein the wheel centers C are in the form of plates provided with convex conical outer bearing faces 40 and 48, and with brackets 41 and ett) to carry the sprocket rack or gear D. In Fig. 7 the webs W of the tread members II and It comprise disks extending from the rim portion of the tread members to the wheel hub, the greater portion of which bears against the wheel center C. Pins 42 project from the outer face of the wheel center through openings 43 formed in the webs \V, and hold these members against relative rotation. A clamping cone 4st bears against the taco ot the web WV, and carries a spring latch 4L5 to engage a series of apertures formed in the web W. The hub of this cone has threaded engagement with a projection to carried by the axle A to which the hub of the Wheel center C is keyed. A l'i'ub cap t7 operates as a jam lock against the threaded hub of the clamping cone.

A wooden-spoke wheelcenter C is shown in Fig. 8, provided with a conical bearing plate 48, which is equipped with projections 49 to support the rack or sprocket wheel I). The webs ot' the tread members II and R are inclined to correspoiid with the taco 48, and are secured thereto by swinging clamps 50 carried by the wheel center C and which. are designed to register with slots t8 and 51 arranged respectively around the edges of the plate having inclined face a8 and the web W. The clamps 50 are shown mounted on hook bolts 52 which are carried by the spokes of the wheel center C.

In the forms illustrated in Figs. 9 and 10, the usual types of conical disk wheel are shown at C extending to the outer edge or perimeter of the disk 53, to which is secured the driving sprocket I), The webs of the It is to be under l U U tread members H and R bear on the inner half of these disks adjacent to the wheel hub. In Fig. 9 this hearing 54 is conical, and pins 55 project from the inner face of web WV and interlock with openings in the disk 53. These interlocking parts hold the web and center against relative rotation. A clamping cone 56 has threaded engagement withv the wheel hub, and bears against the outer face of themember st of the web W and securely clamps it to the wheel center.

This cone is preferably provided with operating handles 57 to facilitate its ma nipulation; Any suitable means may be provided for holding the threaded hub of the cone against backing off, the means here shown being'in the form of a. flange 58 carried by a hub cap 59 which is threaded into the end of the wheel hub. 1

Fig. is similar to Fig; 9, except that J1 1.

the webs W or the tread members have cylindrical bearings on the hub of the wheel center C as shown at 60- and vertical bearings against its web as shown at (ll respectively. The clamping cone 56 is similar to thatshowu 1 in F 9, except that the periphery thereof is provided with a plu- Y rality of teeth 62 designed to vreceive a stitutes a: sepa a tread members spring latch 63 carried by the web Vi".

In the modifications shown in Figs. 11 and 12, wheel centers C are illustrated as having cylindrical contact faces for the tread members H and R, which faces are herein designated 64: and 6% respectively in the two figures. These contact faces are of large diameter and comprise the outer face of the rim of the wheel center C, the tread members H and R in these forms being made in the form of shallow annular rings 65 and 65 which are preferably channel-shaped in cross-section and have mounted oversaid channels tire-lit: rings or plate 66 and 66 respectively, the plate 66 being shown in Fig. 12 as made. integral with the channel while in Fig. ll. it cone member. These shallow are sli )ped over the rim of the wheel center and'held against an o (37 forn'ied at the inner edge of the cylindrical bearing face of the wheel center, and are secured by a clamping ring 68 threaded around the outer portion of the wheel-center rim. These'clan'iping rings carry operating handles 69 to facilitate their application and removal.

The forms shown in Figs. 13 and let also have cylindrical cont-acting faces between the tread members and the wheel'center such faces being of relatively small diameter compared with those shown in Figs. ll and .12, and comprising the outer face of the wheel hub 70 and the inner face of hub member or sleeve 71 carried by the web W.- In this adaptation of the invention, the web or spoke portions of the wheel structure constitute a part of the interchangeable tread members H and R, while in the forms shown in Figs. 11 and 12, the web and spoke portions are a part of the permanent wheel center C. As shown in Figs. 13 and 1%, these spoke portions of the tread members occupy the greater part of the diameter of the wheel, and terminate adjacent to the center of the wheel in tubular hub portions 'Zl which are designed to slip over the hub 70 of the wheel center C and be drawn tightly against the vertical web of said center by jam nuts threaded around an extension of the axle and by washer plates 72 engaging the outer ends of these tubular portions. The hub 70 of the wheel center C is held to a drivingiit on the axle by the usual castle-nut N and washer w.

In the form shown in F ig. 15, the wheel center C is mounted on the usual journal J of a fixed axle F or swinging wheel-pin. This center has a wide rim 73 stiffened by ribs 74 which connect it to the wheel web and hub. The wide outer face of rim 723 has tapered ribs 75 running across its face at right angles to its direction of rotation. These ribs 75 afi'ord bearings for the under faces of the tread members H and R, which in this form of the invention are shown arranged side by side, being slipped over the tapered ribs to occupy tight operating positions. A clamping dish '76 engages the outer face of the highway tread member and holds the two members H and R a: list the tapered edges of the ribs 75. Between said ribs, short projections 77 and 77 de pend respectively from the under faces of the members H and R and are designed to engage one or both sides of the adjacent bearing ribs 7 5 in order to prevent relative rotation ofthe tread men'ibers and the wheel center It to be noted that in this form of the invention as well as that shown in F 16, 17, 18. 19, that the tread menu hers H and R in their working positions are niminted side by side, thus afi'ordi 3 width of track for highway service Sllllhulllllitll v wider than for railwa track service. that is, the distance ljietween the highway tread is substantially wider than the standard 55 railway track gauge. 'his feature advantageous in stablizing the highway load against rocking and iips etting, and in obtz'iining a con'iparatively large tire hearing area on the highway. Two tread diameters are shown for the highway tread menr ber H, the smaller of which is shown in full lines and the larger in dotted lines, the full line tread member being of less diameter than the railway treat member R, and the dotted line member is of greater dian'ieter than said railway tread member.

iVith the parts in the position shown in Fig. 15, the wheel may be used for railway track service without removing the full 1 member H.

line tread'member- H; but beitore the wheel goes into highway service,;the railway member R must be removed. On the other hand, when the highway tread member with the dotted line tread is used the railway tread slanting web 79 having outside bearingribs 80 and 81 to. carry the tread members Rand H, respectively. These ribs all'ord an intermittent c: iudrical rib-hearing for the rail ray tread; member It, and an intermittent conical rib-bearing for the highway Two clmnping cones. 82 and 83 are employed to hold the. tread members in position, the clamp 85 being shown deep and 82 shallow. A rib 83 around the under face of It stops the flanged tire R at the proper track gauge.

The forms shown in Figs. 1-7- and 18 are similar to those illustrated in Figs. 3 and 4-,

except that they include a double throw clamping mechanism similar to that shown in Fig. 5. The tread members have inclined: webs IV which bear against the concave conical: face S l of the wheel center C. I11 Fig. 17 the web85 of the wheel center has arranged at interi 'als around the inner edge thereofdisplaced portions 86 which operate as a seat and centering device for the inner edge of the webs W ofthe tread members. In Fig. 18 this centering device is formed by pins 86 projecting from the underside of the web of the wheel center C. These pins enter notches 87 in the perimeter of the tread webs IV to prevent rela tive rotation of the wheel center and tread members.

In Fig. 17, the separate partsare locked against relative rotation by means of keys 9;) and 93 extending through the doubletnrow thread; or tne clamping mechanism and by pins 88 projecting from the web \V of the tread member and entering slots 89 in the cone member 87. This cone member has ahub 90 which may have left-hand threaded engagement with a clamping nut and hub cap 91, which, in turn, may be right-hand threaded nto the hub 92 of the wheel center. After these parts have been tightened up they may be secured in this position by any suit-able means, keys 93 and 933 being here shown for this purpose. These keys are inserted in holes and slots arranged at intervals around the external and internal threads of the clamping nut, thus locking together the hub 90 oi the cone clamping member and hub 92 of wheel cen ter C. The keys are shown held by a cotter pin 9 1: which passes through the keys and the squared extension of the clamping nut.

Idle-modifications illustrated in Figs. 17

and 1 8. show forms similar to those, shown. in Figs. 17 and 18, the difference being that the treads- H and are arranged side by side. and separated laterally by positioning them laterally in opposite directions from their clamping flanges. These clamping flanges for each tread engage the same bear-1 ing face on the wheel center C, hile in Figs. 15 and 16, the tread. members H and R engage ditl'erent bearing faces on wheel: center C.

The forms ot the invention shown in Figs. 19 and 20 are similar to those shown in Figs; 9 and 10 as regards the bearing otl the tread members on the wheel center C, the difference being that, in Figsf19 and 20, the structure shown con'iprists an internally driven roller-bearing hub 96 of the usual automotive design. 97 secures the webs IV ofi thetread men-ibers to the conical; bearing face 98 01- the wheel A swinging clampi bolt center C as shown in Fig. 19, while: in Fig.

of the wheel center, and: carries a latch 102 which engages a rack 103 mounted 011 the.

angle 101.

Fig. 19 shows a modification of the form illustrated in Fig. 19, and is somewhat similar to the form shown in Fig. 17*, in which the two treads are separated laterally so that the gauge or track width ofthe highway tread II is substantially greater than that of the railway tread R. Both of these treads have interchangeable clamping flanges IV to contact with the same conical fitting face 104 ofthe wheel center C, which face is here shown convex. flanges IV are held against the fitting face 10 1 ofthe wheel center by a clamping" cone 105 threaded around the wheel'hub.

The clamping ill) In Fig. 20. the two treads'H andR are separated laterally, and at the same time,

ably less than that of R as shown in Fig.

20, acts in transmitting greater drivin power in this service. Clamping cones of different depth hold the webs IV of tread members H and R against separate vertical bearing faces of wheel center C.

In Figs. 21 and 22 is sliownthe usual auto motive construction for roller bearing wheel centers mounted on swinging wheel-pins or fixed axles F. In Fig. 21 the disk 106 of the wheel center C has a convex (JOIHCZLIOU'CQI bearing face for contact with the webs IV relative rotation.

seat 107 for the tread members.

of the tread members, which members are clamped thereto by right and left threaded double-throw clamping device and locking arrangement similar to that illustrated in Fig. 5.

The form shown in F 22 is similar to that shown in Fig. 21, the difference being thatin this form the web 106" is vertical and carries about its perimeter a cylindrical The clamping ring 108, which is shown equipped with operating handles 108, has a continuous angular contact adjacent to the inner edge of the web IV as shown at 109. I'Vhile this contact is shown continuous, obviously it may be intermittent if found desirable.

In the form shown in Figs. 23 and 24, the structure is similar to that shown in Figs. 13 and 14, except that in this case the usual automotive construction is included comprising a revolving hub 110 for the wheel center C. This hub is mounted on roller bearings and driven by a shalt enclosed within a tubular housing carrying the bearings. In Fig. 23, the webs IV of the tread members R and H are made S-shaped in cross-section and have stiffening ribs 1.11 formedby radial displacements made in these webs.- The -webs are also provided with a plurality of apertures 112 with which are interlockingly engaged projections 113 carried by the wheel center and which hold said center and web against relative movement.

In Fig. 24, the usual construction for wooden wheels is shown, the hubs of the tread members 110 being equi ped with metal bushings 11st to provide durable contact faces adapted to slip over the outer face of the hub 110 of the wheel center C, and to .be held in position by a clamping cone 115. The inner edges of the hubs 110 are offset or slotted to engage projections 110 from wheel center Q. in order to prevent In Fig. 2%, the highway tread H has 'the inside position relative to the railway tread R, whereby a narrower gauge is provided for the former than for the latter. This arrangement is particularly adapted to vehicles of the smaller type, or to such trucks or conveyances as can effectively use a narrower d ance bet *cen its highway wheel tread than the standard 56 /5 track gauge. It is of course to be understood that, when the service requires, the tread diameters of H and B may be substantially different.

In Figs. and 26, a type of wheel is shown in which the tread members II and It surface engaging member 118 moi'inted thereon preferably by shrinking.

In Fig. 25, the under-faces of the tread mem ers H and B have inclined clamping surfaces 119 which bear against and are clamped to the conical bearing face 120 of the wheel center 0, while in the forms shown in Fig. 26 these bearing faces are made cylindrical as illustrated at 119 and are slipped over themetal faced wooden rim 121 of the wheel centerC. In both of these figures the tread members are held in place by clamping disks or cones 122 having rim edge contact with the offset or short ribs on the outer face of the tread members. These clamping cone-e 122 are equipped with a cylindrical hub 1215 which encircles a retaining ring 12% designed to hold the wheel center C to keyed position on the revolving axle A. This retaining ring l2et'has threaded engagemcnt with a projection 125 on the end of the axle. This projection also carries a clamping ring 126 which engages the edges of the hub of the clamping cone. A combined hub cap and jam nut 12'? threaded around the axle extension and serves to lock the clamping ring in position.

In the form shown in Fi 25. the wheel center C includes a cast or forged hub 128,

to which is secured preferably by riveting or welding a thin plate disk having radial ribs 130 formed by displaced portions around the wheel, said ribs acting to stiffen the web and rim of the wheel center (1. The outer face of the rim 120 of the wheel center has a rib 131 designed to fit in a groove 132 formed in the underside of the tread member, so that these parts may be locked against relative rotation.

A form similar to that illustrated in Fig. 25 is shown in Fig. 25, in which the inner under face of a standard railway tire R and highway tire H abut a narrow conical face 133 of the wheel center C. while the under face adjacent to its outer edge contac with av narrmv cylindrical face '1 1 of i' rim C. This rim is formed from a sheet metal plate and is carried by the ends of the spokes S. A clamping disk or cone 135 holds these tires. in operative position, and has its peripheryslotted as shown at 136 to engage pins 137 projecting from the outer face of the member IV.

A modification of the form shown in 26 is illustrated in Fig. 26, in which a metal wheel center C is shown. in this form the tread members H and It and the clamping plates 138 are made integral.

' A slightly different form of the invention is illustrated in F ig. 27, in which a wheel center C is shown having a flange 139 extending outwardly from one edge its rim and designed to engage the inner edge of the tread members H and R. The outer the tread members.

edge of these.- treadmembers are engaged by a clamping cone 140 which holds the memtread and wheel center C.

In Fig. 28, a ribbed cast wheel center (l is shown of the usual type for heavy auto trucks. A wide l go or rib 141 provid a vertical clamping face for the webs l of:

One or more pins 142 project laterally from this flange 14-1 and interlock with corresponding holes formed in the webmembers VJ. These pins also extend through openings 14:3 tormedin the edges of a clamping cone 144.. This cone is designed to hold either one or two webs of the tread members tightly against the clamping face of the flange l ll. The hub 14-5 of the cone is internally threaded to form part of a double throw rotary clamping mechanism similar to that shown in Fig. 5. This form ofthe invention comprises two separate tread members H for highway service and a third separate tread member it for railway service. One or both of the highway tread members may be used according to the load carried and theunit pressure desired on the highway. This wide wheel. tread is particularly desirable for. wheels of small diameter designed for heavy loads.

In the several figures, various kinds of treads are shown, and obviously any. desired form may beused. It is to be understood that. the highway and railway treads are interchangeable, the highway treads in the drawings being shown in full lines while the rim portion of the railway treads which may be substituted therefor are shown in dotted lines. It will be understood also, that all clamping flanges XV shown in full lines are intended to represent the clamping flange fer the railway tread R as well {S tor the highway tread H.

It will thus be seen that in all the forms shown, the wheel structure includes a wheel center and inl'crchangeable tread members adapted for either railway service or high way service as is desired, and the means employed for effecting this conversion is such as to permit the change to be accomplished with great speed and se.

l l ithout further description, it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in; the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims I claim;

1. A convertible wheel structure for vehicles comprising a wheel center, t read members, and cent-rally located means for interlocated member to hold said parts together.

4;. A. convertible wheel structure for vehicles con'lprising a wheel center, interchangeable railway and highway tread membcrs to coact with said center, and an annular member greatcr in diameterthan the wheel hub and extending to the wheel hub to hold and to release said parts.

5. A convertible wheel structure for rehicles comprising a wheel center, interchangeable railway and highway tread members to coact with said center, and clamping means for securing said members to said center, said means having a centrally located member.

(l. A convertible wheel structure comprising a wheel center, separate quickly interchangeable railway and highway tread mornbers coacting with said center, and a member extending to the wheel hub and having a rotating clamping action concentric with the wheel, for holding. ti ghtencd operating position.

7. A convertible wheel structure for vehicles comprising a wheel center, interchangeable ailway and highway tread members to coact with said center, a centrally.

located clamping member and means for limiting the rotation of said tread members relative to said center.

8. A convertible wheel structure for vehiclcs com iirisii'ig a wheel center, interchangeable railway and highway tread mom.-

wheel center, having a radially disposed.

web or spoke portion, and intercliangeable appliances abutting said web and. means lier detachable connection with said center to adapt it for use on a railway track or on a higln ay.

said tread members in.

fill

llu

iii

11. A convertible wheel structure for vehicles comprising a wheel center, interchangeable appliances for said center, one of which is adapted for railway tracks and the other for highways, and clamping means for connecting said appliances with said center, said clamping means having a portion extending adjacent to the wheel hub.

12. A convertible wheel structure for vchicles comprising a wheel center, interchangeable appliances for said center, one of which is adapted for railway tracks and the other for highways, and centrally located rotating clamping means for connecting said appliances with said center.

13. A wheel structure convertible to railway and to highway service, comprising a wheel center having a radially disposed web orspoke portion, separate tread members interchangeable with each other and fitting said web, one of said members being adapted to run on a railway track and the other on a highway.

14. A wheel structure convertible to railway and to highway service comprising a wheel center, a separate member comprising a standard car wheel tread and flange for detachable mounting on said center to adapt the wheel structure to run on a railway track, and another tread member interchangeable with said ca-r wheel tread to adapt the wheel structure to run on the highway, said interchangeable treads having radially disposed portions to afford a bearingon said'wheel center.

15. A- wheel center for vehicles, a coacting tread member separate from said center and adapted to run on railway track, and another member. interchangeable with said track memberand adapted to run on the highway, said tread members contacting with the wheel center within a cylindrical surface coaxial with the wheel center and intersecting the inner most portion of its adaptable to run on railway track and on the highway, the tread portions of said wheel being separate from the wheel center and held in a tight operating position by clamping means extending adjacent to the Wheel hub.

18. A wheel center for vehicles, and separate quickly changeable railway and highway tread members adapted to coact with said center, within a cylidrical surface coaxial with the wheel center and intersecting the inner mostportion of its perimeter.

19. A wheel center for vehicles, a member separate from said center and having a. standard car wheel flange, and another member interchangeable with said flanged member and adapted to run. on the highways, a portion of said member connecting with said wheel center within a cylindrical surface coaxial with the wheel center and intersecting the innermost portion of its perimeter.

20. A vehicle wheel having a hub and a radially disposed web or spoke portion, a detachable integral annular tread member adapted to contact with said hub or web portion, and centrally located clamping means.

, 21. A vehicle wheel having a hub and a radially disposed web or spoke portion, a releasable tread member laterally opposed to said web and contacting with its outer face, at least a part of the perimetrieal width of said web or spoke portion to stand free from the underside of said tread member around its entire circumference.

22. A vehicle wheel having a hub and a radially disposed web or spoke portion, a quickly releasable integral annular tread member laterally opposed to and contacting with said web, and centrally located clampmg means.

23. A vehicle wheel having a hub, a radially disposed web or spoke portion, two detachable tread members, and clamping means comprising a right hand and a left hand screw lying on the same side of said web or spoke portion.

24'. A vehicle wheel having a hub and aradially disposed web or spoke portion, andtwo interchangeable tread members to adapt said wheel for use on a railway track and on the highway, said tread members contacting with the wheel within a cylindrical surface intersecting said web or spoke portion at their most distant extremity on said hub. and releasable clamping means to hold said tread members in tight operating position.

In testimony whereof I hereunto affix my signature.

SAMUEL G. THOMSON. 

